Obesity is well known as a chronic disease caused by various factors whose origins have not yet been clearly discovered. It is understood that obesity induces hypertension, diabetes mellitus, coronary heart disease, gall bladder disease, osteoarthritis, sleep apnea, respiratory disorder, endomerial, prostate, breast and colon cancer and the like.
According to the NIH Report (Clinical Guideline on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults, 1999, NIH), about 97,000,000 Americans suffer from overweight and obesity, and the number of patients of type II diabetes mellitus associated with obesity, reaches about 15,700,000. Moreover, it is also reported that about 200,000 people die of diseases associated with obesity each year (Dan Ferber, Science, 283, pp 1424, 1999).
Diabetes mellitus is one of the most widespread chronic diseases in the world, which impose a substantial expense on the public as well as on patients of diabetes mellitus and their families.
There are several types of diabetes mellitus that are caused by various etiological factors and whose pathogenesis is different from each other. For example, genuine diabetes mellitus is characterized by high level of blood glucose and glycosuria, and is a chronic disorder of carbohydrate metabolism due to a disturbance of the normal insulin mechanism.
Non-Insulin-Dependent Genuine Diabetes Mellitus (NIDDM), or the type II diabetes mellitus is found in adults who have insulin-resistance in a peripheral target tissue, despite of normal generation and function of insulin.
Non-Insulin-Dependent Genuine Diabetes Mellitus (NIDDM) is caused by three major metabolic disorders, i.e., insulin-resistance, functional disorder of insulin secretion stimulated by nutrients, and overproduction of glucose in liver. Failure to treat NIDDM, resulting in losing control of blood glucose levels, leads to death of patients from diseases such as cardiovascular disease, and/or may cause late complications of diabetes, such as retinopathy, nephropathy or neuropathy.
Accompanying diet-exercise therapy, NIDDM therapy uses sulfonylurea and biguanidine compounds to control blood glucose levels. Recently, therapeutic compounds such as metformin or acarbose have been used for treating NIDDM. However, diet-exercise therapy alone or even combined with chemotherapy using such compounds fails to control hyperglycemia in some of the diabetes mellitus patients. In such cases, these patients require exogenous insulin.
Administration of insulin is very expensive and painful to patients, and furthermore, may cause various detrimental results and various complications in patients. For example, incidences, such as, miscalculating insulin dosage, going without a meal or irregular exercise, may cause insulin response (hypoglycemia) and sometimes the insulin response occurs even without any particular reasons. Insulin injection may also cause an allergy or immunological resistance to insulin.
There are several methods for preventing or treating obesity or diabetes mellitus, including diet-exercise therapy, surgical operation and chemotherapy.
Diet-exercise therapy involves a low-calorie and low-fat diet accompanying aerobic exercise, but this therapy requiring a regular performance is hard to continue until achieving the goal.
Despite of instant effects, a surgery for physically removing body fat has limitations due to the risk and cost involved in a surgical operation and insufficient durability of the effects.
As one of the most promising therapies currently developed, pharmacotherapy can reduce blood glucose level, inhibit absorption of glucose, strengthen the action of insulin or induce the decrease of appetite. The medicines that have been developed so far use various physiological mechanisms for the prevention and the treatment of obesity and diabetes mellitus.
Among said various medicines, dietary fibers are the most useful medicine for prevention or treatment of obesity because no damage to the human metabolism-balance and use natural substances.
Microorganism dietary fiber is produced using microorganisms, such as, Gluconobacter sp., Agrobacterium sp., Acetobacter xylinum, A. hansenii, A. pasteurianus, A. aceti, Rhizobium sp., Alcaligenes sp., Sarcina sp., Streptococcus thermophilus, Lactococcus cremoris, Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus sake, Lactobacillus reuteri, Lactobacillus lactis, Lactobacillus delbrueckii subsp., Lactobacillus helveticusglucose var. jugurti, Leuconostoc dextranicum, Bulgariscus sp., Campestris sp., Sphingomonas sp.
Dietary fiber produced by these microorganisms is used as stabilizer, thickening agent, emulsifier, hygroscopic agent of various foods and raw materials of cosmetics and pharmaceuticals. Microorganism cellulose, xanthan, acetan, guar gum, locust bean gum, carrageenan, alginate, and agar obtained from seaweed are commercialized.
Lactobacillus sp. strain is the major component of normal microbial flora in the human intestines. Its significant roles for maintaining digestive organ and for healthy environment of the vagina, have been well known. [Bible, D. J., ASM News, 54:661-665, 1988; Reid G. and A. W. Bruce, In H Lappin-Scott (de.), Bacterial biofilms, Cambridge University Press, Cambridge, England, p. 274-281, 1995; Reid G., A. W. Bruce, J. A. McGroarty, K. J. Cheng, and J. W. Costerton, clin. Microbiol. Rev., 3:335-344, 1990]. Generally, Lactobacillus strain inhabits in digestive organs (L. acidophilus, L. intestinalis, L. johnsonii, L. reuteri et al.,), muscosa of the vagina (L. vanginals, L. gasseri), food (wine-L. hilgardii), lactobacillus beverage (L. kefir, L. kefiranofaciens), cheese (L. casei), vinegar (L. acetotolerance), the oral cavity (L. oris), yeast (L. sake, L. homohiochi), fruit juice (L. kunkeei, L. mali, L. suebicus), fermented sausages or fish (L. farciminis, L. alimentarious) et al.
Many people take health complementary food containing a Lactobacillus sp. strain in order to maintain healthy intestines and to prevent urogenital tract infection. Recently, in addition to the prevention of the diarrhea, constipation and urogenital tract infection, various probiotic activities of Lactobacillus, such as, control of immunity, control of cholesterol level in blood, prevention of cancer, treatment of rheumatism, alleviation of sensitivity on lactose or effect for atopic dermatitis, have been reported and thus, have attracted more attention.
According to the U.S. Public Health Service Guideline, all of the 262 Lactobacillus deposited in ATCC are classified as “Bio-safety Level 1,” which stands for no potential risk, which has been known up to now, causing diseases in human or animals. There is no harm to human body among approximately 60 strains of Lactobacillus. 
Recently, there has been a rapid progress in the research for an extracellular polysaccharides produced by Lactobacillus. It has been reported that a process of producing dietary fiber in these strains are very complicated because a lot of genes are mediated in the process, and the amount of dietary fiber thus produced are very low (Int. J. Food Microbiol., March 3 40:1-2, 87-92, 1998; Current Opinion in Microbiology, 2:598-603, 1999; Appl. Environ. Microbiol., February 64:2, 659-64, 1998; FEMS Microbiol. Rev. April 23:2 153-77, 1999; FEMS Microbiol. Rev. September 7:1-2, 113-30, 1990).
As mentioned above, although there have been various researches and efforts to develop drugs for treatment or prevention of obesity and diabetes mellitus, their results were not satisfactory. Various chemical substances mentioned above, have been developed for treatment of obesity and diabetes mellitus, but still suffer from various side effects. These drugs forcibly discharge body fat together with valuable proteins. Consequently, any one single drug for treatment or prevention of obesity and diabetes mellitus at the origin thereof does not exist yet.
Therefore, the object of the present invention is to provide microorganisms capable of living within the intestines and converting oligosaccharides produced by the digestive enzymes into non-digestible polysaccharides, and thereby remarkably reducing the amount of oligosaccharide absorbed into the intestines.
Another object of the present invention is to provide a pharmaceutical composition comprising at least one of said microorganisms in an amount effective to prevent or treat obesity and diabetes mellitus and a pharmaceutically acceptable carrier.
Another object of the present invention is to provide a food composition containing the microorganisms as an active ingredient.